Doppler ultrasound systems are valuable diagnostic tools for investigation of vascular blood flow pattern and velocity. Error in blood velocity measurements made by Doppler instruments will cause probable misdiagnosis in clinical practice.
There are different phantom designs for evaluation of the performance and QC of Doppler Ultrasonography systems and the string phantoms were widely used because of their ability to precise calculation of target velocity.
String phantom consists of a moving string with known velocity as a target inside a water tank to mimic blood flow inside the vessels of the body.
There are several parameters defining the position of target inside the water tank in relation to the ultrasound beam. These parameters are target velocity, target angle and target depth.
All string phantoms had three main variable parameters of target angle, target depth and target velocity but only the target velocity is independent and hence target angle and target depth were not independent.
During procedure of QC of Doppler ultrasonography instruments it is necessary to alter the target depth and target angle by phantom. When the operator desires to choose different target angles for a constant value of target depth, altering the target angle will alter the target depth and it is time consuming.
Therefore it would be desirable to eliminate the above mentioned drawback in Doppler ultrasonography phantoms and introduce a phantom with independent parameters.